Cooperative Multicast and Broadcast at the Tactical Edge


Wireless multicast is expected to perform a prominent role in tactical communication networks. However, multicast throughput has long been a notorious performance bottleneck in wireless net- works. Due to path losses and shadowing, the link quality at some receivers can be much worse than those at others. This is especially so in contested RF environments. In order to maximize the chance of successfully delivering packets to all receivers, existing wireless systems always employ the most conservative rate (a.k.a. base rate) among all available modulation and coding schemes (MCS) to send packets in the link layer. Using the base rate fundamentally limits the throughput of wireless multicast, which in turn restricts the situational awareness information sharing in tactical edge networks. Besides the problem of low throughput, it is also difficult to implement reliable wireless multicast. Handshaking in reliable transmissions require receiver feedback. For wireless multicast, feedback from multiple receivers for each frame is resource-consuming and hard to co- ordinate. Therefore, multicast packets in IEEE 802.11, for example, are always transmitted at the base rate without acknowledgement.

In short, developing a comprehensive scheme for high throughput and reliable wireless multicast for edge networks is still an unsolved problem that will be addressed with our proposed Cooperative Multicast and Broadcast at Tactical Edge (COMBAT) technology

The material is based on research sponsored by the Office of Naval Research under agreement number N00014-16-1-2191. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Office of Naval Research, or the U.S. Government.